A wireless communication system typically includes a plurality of access points (APs), (i.e., base stations) which are connected to each other through a wired network, (i.e., a backhaul network). In some cases, directly connecting a given AP to the wired network is more desirable than indirectly connecting the AP to the wired network by relaying a data packet to and from neighboring APs, such as in a mesh network.
A mesh wireless local area network (WLAN), (i.e., mesh network), includes a plurality of mesh points (MPs), each of which is connected to one or more neighboring MPs with wireless links such that a data packet may be routed using the intra-mesh radio resources via one or more hops to a destination. The mesh network has an advantage of ease and speed of deployment because radio links between MPs can be deployed without having to provide a backhaul wired network for each AP.
A mesh network usually belongs to a bigger local area network (LAN) which can include different types of LAN technologies, (e.g., IEEE 802.3 Ethernet, IEEE 802.5 Token Ring, IEEE 802.11 WLAN, or the like). A mesh portal is an MP that provides interconnectivity between the mesh network and the rest of the LAN. The LAN resources that do not belong to the mesh network are referred to as extra-mesh LAN resources. A mesh network having two or more mesh portals is a multi-portal mesh network. In a multi-portal mesh network, the portals could be interconnected via the extra-mesh LAN resources.
Two types of traffic exist in a mesh network: Intra-mesh traffic that is destined to nodes within the mesh network, and extra-mesh traffic that is destined to nodes lying outside of the mesh network. A mesh network that does not have a mesh portal can only support intra-mesh traffic, since with no mesh portal there is no way for the packet to be forwarded outside of the mesh. On the other hand, a mesh network with one or more mesh portals can support both intra-mesh traffic and extra-mesh traffic.
Routing intra-mesh traffic is referred to as intra-mesh routing and consists of determining the best path between any two MPs of the mesh network throughout the mesh. Similarly, routing extra-mesh traffic is referred to as extra-mesh routing and consists of determining the best path between any MP and its best, (e.g., closest), mesh portal.
Although a mesh network is advantageous in terms of its ease of deployment and low cost of establishing a backhaul network, the radio resource capacity of the mesh network is limited. Since the mesh network can use multiple hops between MPs to relay a packet from one node to another, a large portion of the channel capacity is used to support the wireless backhaul. Thus, the capacity of the mesh network decreases exponentially as the number of hops that the packets need to reach their destination increases.